A known electrical terminal 101 for connection with a wire is disclosed in U.S. Pat. No. 4,003,623 B and shown in FIGS. 11 and 12.
The known electrical terminal 101 shown in FIG. 11 includes a pair of side walls 104, 105 that extend from opposite sides of a base 103 and face each other. The shown embodiment is substantially U-shaped and includes a cavity 102 therein. The electrical terminal 101 is made by stamping and forming a metal sheet. The base 103 has an elongated shape for receiving wires W1 and W2 (see FIG. 12). A plurality of serrations 106 are successively positioned from the upper end of the one side wall 104 to the upper end of the other side wall 105 and disposed along the inner surfaces of the pair of side walls 104, 105 and the base 103. Hence, the serrations 106 formed on the side wall 104 and the serrations 106 formed on the side wall 105 are opposed each other and extend in the same direction. Each of the serrations 106 extends in a direction perpendicular to a length of the base and a direction in which the wires W1 and W2 (see FIG. 12) extend when positioned in the cavity 102.
After the two wires W1 and W2 are inserted into the cavity 102, the pair of side walls 104 and 105 are deformed, as shown in FIG. 12, to crimp the electrical terminal 101 onto the wires W1 and W2. Then, the side wall 104 wraps around the periphery of the wire W1, while the side wall 105 wraps around the wire W2. In this situation, each serration 106 bites into the wires W1 and W2.
Another known electrical connector 201 for connection with a thin wire like a coil winding is disclosed in Japanese Patent No. JP S52-114987 A, as shown in FIG. 13
As shown, the known electrical connector 201 includes a housing 210 having a terminal receiving section 211 and an electrical terminal 220 for insertion into the terminal receiving section 211.
First grooves 212 are disposed along both upper sides of the terminal receiving section 211 of the housing 210. Second grooves 213 are disposed along both lower sides of the terminal receiving section 211 of the housing 210. In addition, a wire wound section 215 is provided at a back side of an upper wall 214 of the housing 210, in order to wind a wire 216 around the wire wound section 215. The wire 216 is a thin electrical insulated wire of, for example, approximately A.W.G #50 having a metal core and an insulator covering the outer part of the metal core.
On the other hand, the electrical terminal 220 is made by stamping and forming a metal sheet, and includes a base 221 having a substantially rectangular flat plate shape. A plurality of lances 221a and 221b are positioned along opposites sides of the base 221. Moreover, the electrical terminal 220 is provided with a front side plate 222 extending obliquely forward from the front end of the base 221 and a back side plate 224 extending from the back end of the base 221 to be folded back obliquely. A side plate 223 extends in such a manner as to be folded back backward from a tip 222a of the front side plate 222. A plurality of serrations 225 are disposed on the surface of the side plate 223. The end of back side plate 224 is positioned between a pair of flanges 223a positioned at both sides of the side plate 223 and folded downward there from. Lances 223b are provided at ends of the pair of flanges 223a, respectively.
Then, the electrical terminal 220 is inserted into the terminal receiving section 211 of the housing 210. Accordingly, the base 221, the front side plate 222, the side plate 223, and the back side plate 224 are inserted into the terminal receiving section 211. Additionally, the lances 223b are pressed into the first grooves 212, respectively, and the lances 221a and 221b are pressed into the second grooves 213, respectively. Moreover, when the tip 222a of the front side plate 222 abuts against an end wall, not shown, of the housing 210, the base 221 is moved in the direction of an arrow, and then the front side plate 222 is turned around a fixed end thereof. Accordingly, each of the serrations 225 formed on the side plate 223 engages the wire 216.
Furthermore, another example of a known electrical connector for connection with a thin wire like a coil winding is disclosed in Japanese Patent No. JP H10-302857 A, as shown in FIG. 14.
The known electrical connector 301 shown in FIG. 14 includes a housing 310, a first terminal 320 press-fitted into a first cavity 311 of the housing 310, and a second terminal 330 press-fitted into a second cavity 312 of the housing 310.
The first terminal 320 is made by stamping and forming a metal sheet, and includes a base 324 press-fitted into the first cavity 311, and a contact part 321 having a gently arcuate shape curved toward a wire receiving surface 313 of the housing 310. A plurality of serrations 322 are disposed on a surface of the contact part 321 and positioned opposite to the wire receiving surface 313. A vertex 323 is formed at the end of the first terminal 320 at the contact part 321 side.
Furthermore, the second terminal 330 is made by stamping and forming a metal sheet, and has a pressing part 331 disposed at the tip thereof to press the vertex 323 of the first terminal 320 toward the wire receiving surface 313.
Then, a wire 330 is disposed between the wire receiving surface 313 and the contact part 321. When the second terminal 330 is press-fitted, the pressing part 331 of the second terminal 330 presses the vertex 323 of the first terminal 320 toward the wire receiving surface 313. This permits the contact part 321 of the first terminal 320 to elastically contact with the wire 330. When the contact part 321 elastically contacts the wire 330, the serrations 322 formed on the contact part 321 engage the wire 330. The wire 330 is a thin insulated electrical wire of, for example, approximately A.W.G #50 having a metal core and an insulator covering the outer part of the metal core
Each of the known electrical terminals 101, 201 and 301 have the following disadvantages.
As for the known electrical terminal 101 shown in FIG. 11 and FIG. 12, the cavity 102 that receives the wires W1 and W2 is large, notably when a thin wire like a coil winding is connected. The pair of side walls 104 and 105 are not completely rounded and some portions remain. This makes it difficult to connect such a thin wire in a stable manner, especially when a single thin wire is connected. Herein, the thin wire denotes a wire having a diameter of for example, approximately 0.02 mm to 0.25 mm.
As for the known electrical connector 201 shown in FIG. 13, it is difficult to narrow the pitch of the base 221, the side plate 223, and the like of the electrical terminal 220 that have a wide width. Furthermore, the housing 210 is necessary in addition to the electrical terminal 220 to connect the wire 216, thereby posing a problem that the number of component parts is large.
As for the electrical connector 301 shown in FIG. 14, the wire 301 for connection is the thin insulated electrical wire of, for example, approximately A.W.G #50 including the metal core and the insulator covering the outer part of the metal core. Therefore, stable connection can be achieved when the thin wire like the coil winding is connected. However, the housing 310 is necessary in addition to the first and second terminals 320 and 330 to connect the wire 301, thereby posing a problem that the number of component parts is large.